JP2008153655A - Wafer inspection equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer inspection equipment which can be further improved in detection speed and detection sensitivity. <P>SOLUTION: The wafer inspection equipment comprises one or more lighting devices (20) arranged in each light path (20a) to irradiate a surface (22) of a wafer (23). A detected light path (21a) is defined by a detection device (21) and the detection device (21) detects data of one or more irradiated areas (26) movable in the scanning direction on the surface (22) of the wafer (23) in a plurality of different spectral ranges. The one or more lighting devices (20) are continuum light sources. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer inspection apparatus, and more particularly to a wafer inspection apparatus including one or more illumination devices for irradiating an illumination light beam in an illumination light path to the wafer surface. Further, a detection optical line is defined, and a detection device having a predetermined spectral sensitivity is provided. The detector records data for one or more illumination ranges on the wafer surface. Here, the light coming from the wafer surface can have a plurality of different spectral ranges.

  The present invention further includes a first illumination device for irradiating the illumination light beam in the illumination light line on the wafer surface, and a first illumination device for irradiating the illumination light beam in the second illumination light line on the wafer surface. The present invention relates to a wafer inspection apparatus including two illumination devices. A first detection device that defines the first detection optical line is also provided. In addition, a second detection device that defines the second detection optical path is provided. The two detectors have a predetermined spectral sensitivity, and data from the illumination range of the wafer surface is detected in a plurality of different spectral ranges.

  In order to improve quality and efficiency in the manufacture of integrated circuits, an apparatus for detecting macro defects on the wafer surface is used. Thereby, the wafer in which the defect is found is removed or post-processed until the quality of the inspected wafer is sufficient.

  An optical inspection apparatus that irradiates an illumination beam onto a wafer surface using an illumination apparatus is known. There is also provided an image recording device for detecting images and data from the illumination range of the wafer surface by means of a plurality of spectral ranges or spectral decompositions.

  German patent application DE 10132360 discloses a device for adjusting the intermediate brightness of colors in the illumination light path of a microscope. The invention is based on the idea that in a microscope using an incandescent lamp similar to a black light, the color temperature of the color spectrum emitted from the incandescent lamp shifts from the blue spectral range to the red spectral range when the input power to the lamp decreases. based on.

  German patent application publication DE 10031303 discloses a lighting device with LEDs.

U.S. Pat. No. 6,847,443 B1 discloses a system and method for detecting surface defects with light having multiple wavelengths of narrow bandwidth. Defects mainly occur in the surface structure formed on the semiconductor wafer surface. A light source, preferably a flash lamp light source, is provided and emits illumination light. The illumination light is divided by a filter into a plurality of selected bands having respective bandwidths. The light is then guided from the optical fiber to a diffuser where it is directed to the wafer surface on the semiconductor. A single camera receives a plurality of images generated in different portions of the spectrum. Images can be generated from both reflected and diffracted light. The image can be stored or compared with an image of a control wafer. The small bandwidth of the illumination light is selected so that the wavelength of the illumination light falls within the maximum sensitivity range of each camera channel. By comparing the measured light intensity with the measured light intensity of the wafer having no defect, the contrast value of each region on the wafer surface is determined. It was shown that the greater the defect, the greater the contrast value. By using a narrow bandwidth illumination light and a corresponding narrow bandwidth detector, the contrast value is significantly improved.
DE10132360 DE10031303 US 6,847,443 B1

In the first known optical inspection device, in the further processing of the color signal detected by the image detection device, if the color image channel of the image detection device is manipulated in an incorrect manner, the noise ratio or individual There is a problem that the S / N ratio is relatively low with respect to overdriving of the color signal.
In Patent Document 1, in order to compensate for the red shift, a variable optical filter having a variable transmitter for red light is provided over the filter range in the illumination optical line. Removing the filter in the illuminating light line causes a blue shift, which is compensated for by the red shift caused by the power drop.
In Patent Document 2, due to the deterioration of the LED material, the intensity and wavelength of light emitted from the LED change over time. In order to achieve uniform lighting characteristics, feedback control is required to maintain the predetermined color temperature and intensity of the LED.
In Patent Document 3, however, the solution principle is insufficient to further improve the detection speed and detection sensitivity.

  One object of the present invention is to provide an apparatus or method that can further improve detection speed and detection sensitivity.

  According to a first aspect of the present invention, the wafer detection device is one or more illumination devices respectively disposed in one illumination light line, and the one or more illumination devices illuminate an illumination spot on the wafer surface. An illumination device that is a continuous light source; a detection device disposed within a single detection beam path that has a predetermined spectral sensitivity and records data from the one or more illumination spots on the wafer surface; An imaging device that generates relative movement between a wafer surface and the detection device, whereby the illumination spot moves in a scanning direction in a zigzag manner and passes (scans) the entire wafer surface And wherein the one or more illumination spots are detected in a plurality of different spectral ranges. .

    According to a second aspect of the present invention, the wafer detection device includes a first illumination device configured as a continuous light source for irradiating an illumination beam toward the wafer surface in the first illumination light line, and a second illumination device. A second illuminating device configured as a continuous light source for irradiating an illuminating light beam toward the wafer surface in the illuminating optical line, a first detecting device defining a first detecting optical line, And a second detection device defining two detection optical lines, wherein the first and second detection devices have a predetermined spectral sensitivity and are movable in the scanning direction on the wafer surface. This data is detected in a plurality of different spectral ranges.

Further advantageous embodiments are the contents of the dependent claims which refer to the respective independent claims, and are referred to where appropriate.
The following are advantageous embodiments.
In the first viewpoint, the following development forms are possible.
A polarizing device may be disposed downstream of one or more illumination devices in each illumination light line. (Form 1-1, Claim 2)
An illumination region having a illumination pattern disposed on a downstream side of the one or more illumination devices and having an illumination pattern on the surface of the wafer that produces a plurality of positionally different ranges with respect to wavelength and / or intensity. Can be formed on top. (Form 1-2, claim 3)
The illuminating device may include a light source that emits light having a plurality of intensity peaks that are discretely formed at different wavelengths. (Form 1-3, Claim 4)
The illumination device can be a continuously adjustable light source so that each can be adjusted to the required wavelength range. (Form 1-4, Claim 5)
The lighting device may include one or more LEDs. (Form 1-5, Claim 6)
The illumination device may be a broadband light source that can be adjusted to the respective wavelength or wavelength range by means of a corresponding filter. (Form 1-6, Claim 7)
The detection device may be a line camera. (Form 1-7, Claim 8)
The detection device can include a trilinear detector with a suitable wavelength filter in each line of the trilinear detector. (Form 1-8, Claim 9)
The detection device may include three photosensitive detection chips arranged in association with the spectroscopic or dispersion device so that each detection chip receives a different wavelength. (Form 1-9, Claim 10)
The detection device includes a two-dimensional photosensitive detection chip having a spectral or dispersive element disposed upstream to direct light in different wavelength ranges onto different detection lines of the photosensitive two-dimensional detection chip. Can do. (Form 1-10, Claim 11)
A beam splitter may be provided to make the light of the illumination device collinear with the detection light path of the detection device. (Form 1-11, Claim 12)
The beam splitter may have a polarization characteristic. (Form 1-12, Claim 13)
The illumination device and the detection device may be arranged such that the illumination light line and the detection light line are inclined at an angle with respect to the normal line of the wafer surface. (Form 1-13, Claim 14)
The angle of the illumination device and the detection device may be adjustable. (Form 1-14, Claim 15)
The one or more illumination devices may generate illumination regions (several spaces) spatially separated in the scanning direction of the wafer surface. (Form 1-15, Claim 16)
In the second viewpoint, the following development forms are possible.
A polarizing device may be provided in at least one of the illumination light lines of the first and second illumination devices. (Form 2-1, claim 18)
A digital modulator for generating an illumination area on the wafer surface is provided downstream of at least one of the two illuminators to generate a range on the wafer surface that is different from each other in terms of wavelength and / or intensity. Can be placed on the side. (Form 2-2, claim 19)
Light from the first illumination device and the second illumination device can be incident on a common illumination range on the wafer surface. (Form 2-3, Claim 20)
Light from the first illuminating device and the second illuminating device can form a range (plurality) spatially separated in the scanning direction of the wafer surface. (Form 2-4, Claim 21)
The second illumination device and the second detection device are arranged such that the second illumination light line and the second detection light line are inclined at an angle with respect to the normal of the wafer surface, respectively. Can. (Form 2-5, Claim 22)
The angle formed by the second detection optical line may be variable. (Form 2-6, Claim 23)
The first or second detection unit can detect monochromatic light or multicolor light. (Form 2-7, Claim 24)
The first and / or the second illumination device may include a light source that emits light having a plurality of intensity peaks discretely formed at different wavelengths. (Form 2-8, Claim 25)
The first and / or second illumination device may be a continuously adjustable light source so that each can be adjusted to the required wavelength range. (Form 2-9, Claim 26)
The first and / or second lighting device may include one or more LEDs. (Form 2-10, Claim 27)
The first and / or second illumination device may include a broadband light source that can be adjusted to a respective wavelength or wavelength range by a corresponding filter. (Form 2-11, Claim 28)
The first and / or the second detection device may be a line camera. (Form 2-12, Claim 29)
Said first and / or said second detection device may comprise a trilinear detector with a suitable wavelength filter in each line of the trilinear detector. (Form 2-13, Claim 30)
The first and / or second detection device may include three photosensitive detection chips arranged in association with the spectroscopic or dispersion device such that each detection chip receives a different wavelength. (Form 2-14, Claim 31)
The first and / or the second detection device has spectral or dispersive elements arranged on the upstream side for directing light of different wavelength ranges (plurality) onto different detection lines of the photosensitive two-dimensional detection chip, A two-dimensional photosensitive detection chip can be included. (Form 2-15, Claim 32)

  According to the present invention, an inspection apparatus for a wafer surface is provided, and the illumination apparatus includes one or more continuous light sources. In another embodiment, a polarizing device is provided in the illumination light path downstream of the illumination device.

  According to another embodiment of the present invention, the above object is also achieved by a device comprising only two illumination devices, each configured as a continuous light source. In addition, the polarizing device can be installed in at least one of the illumination light lines of the two illumination devices.

  The illumination device may include a light source that emits light having a plurality of discrete intensity peaks formed at different wavelengths. In addition, the illuminating device can include a continuously adjustable light source that can each be set to the required wavelength range. It goes without saying that the spectral width of the required wavelength range can meet the requirements necessary for the inspection.

  The lighting device may further include LED lighting. This illuminating device can be provided as a light source in a broadband band where each wavelength or wavelength range is adjustable with a corresponding filter.

  The detection device can be configured as a line camera. The detection device includes a trilinear detector, and each line of the trilinear detector is provided with a suitable wavelength filter. Further, the detection device may include three photosensitive chips arranged in relation to (by way of example) a spectroscopic (or dispersion) device (eg a prism) so that each chip senses a different wavelength. The detection device may also include a two-dimensional photosensitive chip having a spectral or dispersive element upstream thereof, with different wavelength ranges being allocated over the range of different photosensitive chips. This detection device can be regarded as an image spectrometer.

  According to the embodiment of the present invention, a beam splitter is used to make the light of the illumination device and the detection light line (beam splitter) of the detection device collinear. The beam splitter used here may have polarization characteristics.

  According to a further embodiment of the present invention, the illumination device and the detection device are arranged such that the illumination light line and the detection light line are each at an angle with respect to the normal on the wafer surface. An arrangement that forms an angle between the illumination device and the detection device may be a bright field arrangement. That is, the angle formed by the illumination optical line with the normal on the wafer surface is equal to the angle formed by the detection optical line with the normal on the wafer surface. In the dark field arrangement, the angle formed by the illumination light line with the normal on the wafer surface is different from the angle formed by the detection light line with the normal on the wafer surface. That is, with respect to this normal line, the illumination light line and the detection light line cross each other at an angle.

  In another embodiment of the present invention, first and second illumination devices and first and second detection devices are provided. In a further embodiment, each lighting device may comprise a continuous light source and a polarizing device may be provided in the illumination light path of the at least one lighting device.

  The two illumination devices can be arranged such that light from the first illumination device and the second illumination device is simultaneously present in the same area of the wafer surface. The illumination light line of the first illumination device can be formed on the same line via the detection light line of the first detection device and the beam splitter.

  The second illumination device and the second detection device may be arranged on a normal line on the wafer surface. Here, the angle formed by the second detection optical line can be adjusted.

  The first detection device may be configured with, for example, monochromatic light so that it can be detected with high resolution. The second detection device is, for example, multicolor light, and may have a lower resolution than the first detection device.

  It is advantageous to arrange the polarizing device in one or more illumination light lines. Furthermore, the orientation of the diffraction grating relative to the polarization direction can be determined using a diffraction grating type structure (so-called zero order diffraction). Similarly, it is possible to determine whether there is a diffraction grating structure on the wafer (and where it is if necessary). This is not achievable at much lower resolutions in the range of greater than 5 μm used in current macro inspections. The use of the present invention is particularly advantageous if the grating period of the structures present on the wafer is in the range of a small illumination wavelength or less.

  A typical example will be described below with reference to the accompanying drawings of the present invention. Further features, objects and advantages of the present invention will be apparent from the accompanying drawings. The same reference numeral indicates the same element or a group of elements or functional bodies having an essentially equivalent effect.

  FIG. 1 shows a system for inspecting a structure on a semiconductor substrate. The system 1 includes the device of the present invention therein. The system 1 has one or more cartridge elements 3 for example for semiconductor substrates or wafers. Images, image data or data of individual wafers or processed semiconductor substrates are recorded in the measuring unit 5. A transfer mechanism 9 is arranged between the cartridge element 3 for the wafer or semiconductor substrate and the measuring unit 5. The system itself is housed in a housing 11 that defines a cradle range 12. In addition, one or more computers for evaluating or processing individual image data are integrated into the system 1. The system 1 includes a display 13 and a keyboard 14. The user can use the keyboard 14 to input data for system control and even input parameters for evaluating data, image data and images from recorded individual wafers. On the display 13, interfaces of a plurality of users of the system 1 are displayed. In addition, the information being measured is displayed on the user interface. The system 1 can take a modular structure so that additional measuring means (not shown) can be added to the system 1. Additional measuring means are available for other inspection methods.

  FIG. 2 is one embodiment of the present invention. This device includes an illumination device 20 that defines an illumination optical line 20a. The apparatus further includes a detection device 21 that defines a detection optical line 21a. A beam splitter (beam splitter) 25 having polarization characteristics is provided to bring the illumination light line 20a on the same line as the detection light line 21a. Therefore, the beam splitter 25 directs the light emitted from the illumination device 20 toward the surface 22 of the wafer 23. The light emitted or reflected from the surface 22 of the wafer 23 reaches the detector 21 along the detection light path 21a. It should be noted that the beam splitter 25 is arranged so that the light emitted from the illumination device 20 strikes the wafer surface substantially vertically. The light from the illumination device 20 illuminates a predetermined range 26 on the surface 22 of the wafer 23. As a result, only the range (irradiation region) 26 of the surface 22 of the wafer 23 illuminated at that time is detected by the detection device 21. The wafer 23 (or semiconductor substrate) is placed on the support means 28 that is configured to be movable. The support means 28 can be configured to be rotatable or movable in two orthogonal directions, such as in the xy axis direction. By providing this moving equipment (or mechanism), the entire surface 22 of the wafer 23 can be inspected using the apparatus according to the present invention. Details of the method of scanning the surface 22 of the wafer 23 will be described later with reference to FIG.

  Referring to FIG. 2, the detection device 21 functions as data reading means, and is connected to a computer 15 for reading, evaluating, or holding detection data via a data line 21b. The data reading means is configured and applied so that continuous scanning of the surface 22 of the wafer 23 is possible using a continuous light source. Here, the reading speed of the data reading means needs to be synchronized with the moving speed of the support means 28 of the wafer 23.

  FIG. 3 is a schematic diagram of one embodiment of the arrangement of the illumination device 20 and the detection device 21 in which the polarization device 27 is arranged in the illumination light line 20a. One or more polarizing devices 27 are arranged between the illumination device 20 and the beam splitter 25. The resolution of the device according to the present invention is emphasized (higher resolution) by this polarizing device 27. Otherwise, this device has the same characteristics as the device shown in FIG.

  FIG. 4 shows another embodiment of the apparatus according to the present invention, which is suitable for high-resolution inspection of the surface 22 of the wafer 23. The illumination device 20 and the detection device 21 are arranged at a small angle 34 with respect to the normal (normal) 30 of the surface 22 of the wafer 23. In this arrangement, the illumination light line 20 a forms a small angle 34 with respect to the normal 30 that is perpendicular to the surface 22 of the wafer 23. Similarly, the detection device 21 is arranged such that the detection optical line 21 a defined by the detection device 21 forms a small angle 35 with respect to the normal 30. An optical device or lens 31 is disposed in the illumination light line 20a, and the light emitted by the illumination device 20 is formed (in a predetermined beam) and formed on the surface 22 of the wafer 23 in a narrow line or correspondingly. The light spot is imaged. The polarization device 27 can be additionally disposed (post-position) downstream of the lens 31. The polarizing device 27 is not necessarily required for the present invention. The polarization device 27 is for enhancing the contrast of recording of image data by the detection device 21. Light emitted or reflected from the surface 22 of the wafer 23 reaches the detection device 21 via the optical device 32, where it is analyzed and recorded in a suitable manner.

FIG. 5-A shows a further embodiment of the device according to the invention. First illumination device 20 ₁ defines a first illumination beam path 20a _1. Further, the second illumination device 20 ₂ to define a second illumination beam path 20a _2. First illumination device 20 ₁ has the associated first detector 21 ₁ is (assigned) it. Second illumination device 20 ₂ has a second detector 21 ₂ associated with it. The first illumination device 20 of the _first illumination beam path 20a _1, beam splitter for bringing the first illumination beam path 20a ₁ to the first detection beam path 21a ₁ and the same line 25 is arranged. The beam splitter 25 is preferably configured as a polarized beam splitter. Second second illumination device 20 ₂ in the illumination beam path 20a ₂ second detector 21 _2, the second illumination light path 20a ₂ second detection beam path 21a _2, the surface 22 of the wafer 23 Are arranged so as to form a first angle 41 and a second angle 42, respectively. The first detector 211 and second detector ₂₁₂ may constitute a monochromatic light (Monochrom) or polychromatic light (polychrom). When the detection devices 21 ₁ and 21 ₂ are monochromatic light, high-resolution detection of the surface 22 of the wafer 23 is possible. When the detection devices 21 ₁ and 21 ₂ are polychromatic light, low-resolution detection of the surface 22 of the wafer 23 is possible. In the illustrated case, the first angle 41 that defines the inclination of the second illumination light line 20a ₂ with respect to the normal line 30 is equal to the second angle 42 that the second detection light line 21a ₂ makes with the normal line 30. Bright field arrangement. A dark field arrangement is also possible, where the first angle 41 and the second angle 42 are not equal. There may be a plurality of embodiments in the configuration of the detection devices 21 ₁ and 21 ₂ . The second detection beam path 21a _2, further placing a dispersion for directing reflected light from the surface 22 of the wafer 23 in each of the sensing elements is a polychromatic light detector (or spectral) element (dispersives Element). FIGS. 8-A, 8-B, 8-C show three different embodiments of possible configurations of the detection devices 21 ₁ and 21 ₂ .

FIG. 5-B shows a possible arrangement of the illumination areas 35 a and 35 b on the surface 22 of the wafer 23. Besides the first illumination device 20 ₁ and the second illumination device 20 _second illumination regions 35a and 35b overlap (not shown) possible (if), FIG. 5-B is illuminated regions 35a and 35b are scanning direction 63 In (with respect) are separated from each other. Since the wafer 23 is disposed on the support means 28, the wafer 23 can move in the x- and y-axis directions, and the illumination areas 35a and 35b are dies arranged on the surface 22 of the wafer 23 (semiconductor chips on the wafer). ) Move on 64.

  FIG. 6 shows a modified arrangement example of the illumination device 20 and the detection device 21 again. In the arrangement of FIG. 6, the illumination light line 20 a and the detection light line 21 a are inclined by an angle 41 and an angle 42 with respect to the normal 30 of the surface 22 of the wafer 23. If the angle 41 and the angle 42 are equal, this is called bright field arrangement. If the angle and the angle 42 are not equal, this is called dark field arrangement. It is particularly advantageous for the user to be able to switch between the two arrangements in response to measurement problems. In some cases, the bright field arrangement may be better suited to solve the measurement problem than the dark field arrangement, and vice versa.

  FIG. 7 shows how the entire surface 22 of the wafer 23 is detected or scanned. One or more illuminators 20 generate an illumination spot 60 on the surface 22 of the wafer 23, which in either one of the illumination areas 35a or 35b of FIG. 5-B when only one illuminator is provided. Equivalent to. The illumination spot 60 is also generated when two or more illumination areas by a plurality of illumination devices are overlapped. The illumination spot 60 can be linear, narrow, any special shape, or symmetrical. If the illumination spot 60 is linear, the length of the illumination spot 60 is longer than its width. In order to scan the entire area of the surface 22 of the wafer 23, the illumination spot 60 moves the wafer 23 in the x direction (scanning direction 63, see arrow in FIG. 5B) and the y direction, thereby zigzag (meander). It is swept (guided) along the line 61.

FIG. 8A is a detailed view of the arrangement of FIG. 5-A, and the detection device is composed of a trilinear detector. The detector 21 ₁ or 21 ₂ is composed of three detection lines 50 ₁ , 50 ₂ , 50 ₃ (parallel to each other with a predetermined pitch or interval) arranged in parallel, and each has a corresponding color filter 51 ₁ , 51 ₂ , 51 ₃ . . By using a trilinear detector, each detection line 50 ₁ , 50 ₂ , 50 ₃ receives each light information of a different color from the surface 22 of the wafer 23 as a color filter or wavelength filter 51 ₁ , 51 ₂ , 51 ₃ . It can be detected by each arrangement.

FIG. 8-B shows another embodiment of the detection device 21 ₁ and / or 21 ₂ , which includes a plurality of detection chips 53 ₁ , 53 ₂ , 53 ₃ . Detection chip _{53 1,} 53 2, 53 _3, each of the detection chip _{53 1,} 53 2, 53 ₃ to receive a different color information, spectral for splitting the incident light spectrum (spectroscopically) to (dispersed ) Are arranged in a spectral correspondence around (near) the device 54. In a special embodiment, the first detection chip 53 ₁ can detect the red light, ₂ a second detection chip 53 can detect a green light, a third detection chip 53 ₃ can detect blue light.

Figure 8-C shows one embodiment of the detection device 21 ₁ and / or 21 _2, detecting device consists of a two-dimensional detection chip 55. In this case, the spectral element 70 is disposed in a second detection beam path 21a ₁ or 21a _2. The spectroscopic (dispersion) element 70 is in the detection light path 21a ₁ or 21a ₂ so that the detected light is imaged in a spectrally split manner on the individual detection lines 71 of the detection chip 55. This is for spatially separating each spectral portion of the detection light. A lens (not shown) can also be arranged downstream of the spectroscopic element 70 to image the spatially separated light on the individual detection lines 71 of the two-dimensional detection chip 55 in a suitable manner. The exemplary embodiment shown here is an image spectrometer.

  FIG. 9A is a schematic diagram showing an illumination device 65 that is another embodiment of the illumination optical line 20a. The illumination device 65 includes a digital modulator 66 (DMD) in the illumination light path 20 a of the light source 67. The illuminating device 65 is arrange | positioned in the illumination optical line 20a. In the arrangement shown in FIG. 9A, the illumination light line 20 a and the detection light line 21 a are at angles of 41 and 42 with respect to the normal line 30 of the surface 22 of the wafer 23, respectively. If the angle 41 is equal to the angle 42, it is called bright field arrangement. If the angle 41 is not equal to the angle 42, it is called a dark field arrangement. This embodiment has the particular advantage that the user can switch between the two arrangements depending on the measurement problem. In some cases, the bright field arrangement may be better suited to solve the measurement problem than the dark field arrangement, and vice versa.

  FIG. 9-B is a schematic diagram of an example of an illumination pattern 85 that may appear on the surface 22 of the wafer 23 using the DMD 66. In FIG. 9-B, the illumination pattern 85 is shown including a plurality of dies 64 disposed on the surface 22 of the wafer 23. The illumination pattern 85 may be configured such that, for example, a (spacing) range 86 between the dies 64 called “street” is illuminated with a different intensity than the dies 64 themselves. It is also conceivable that the range of the illumination pattern 85 is configured to be different from each other depending on the wavelength and / or intensity.

  FIG. 10 shows the spectral composition of the illumination light when the illumination device 20 is configured as a spectrally linear light source. In FIG. 10, the horizontal axis 82 indicates the wavelength λ, and the vertical axis 83 indicates the intensity I. It can be readily seen that spectrally linear light sources show different peaks 80 at different wavelength λ positions. From the peak (s) formed by the spectrally linear light source, it is clear that the surface 22 of the wafer 23 is illuminated with a certain spectrum (characteristic or pattern).

  11, the horizontal axis 90 indicates the wavelength λ, and the vertical axis 91 indicates the intensity I. A continuously adjustable light source exhibits an intensity characteristic 92 that is essentially independent of the wavelength λ (flat or gentle). The continuously adjustable light source is controlled such that a wavelength range or wavelength peak 93 selected by the user is emitted. The surface 22 of the wafer 23 can be illuminated with this wavelength peak (or band) or spectral spacing.

  FIG. 12 shows the illumination intensity when the illumination device 20 is composed of LEDs. Again, the horizontal axis 100 represents the wavelength λ and the vertical axis 101 represents the intensity I. If only one type of LED is used, a clean peak 102 is seen at wavelength λ. The wafer surface is illuminated with this intensity peak. It goes without saying that a plurality of LEDs that emit light of different wavelengths can be used. In that case, it is obvious that a plurality of intensity peaks appear at different wavelengths in the diagram of FIG.

  FIG. 13 shows a broadband light source using a filter, preferably a comb filter (Kammfilter). First, a broadband light source emits light that is essentially independent of wavelength λ. This is shown in FIG. The horizontal axis 110 is the wavelength λ, and the vertical axis 111 is the intensity I. The comb filter has an effect of transmitting light only in a narrow wavelength range (band). As shown in FIG. 13B (the horizontal axis 110 is the wavelength λ and the vertical axis 111 is the intensity I), the comb filter produces strong peaks (plurality) at different wavelengths. By combining the broadband light source and the comb filter, the result shown in FIG. 13C (the horizontal axis 110 is the wavelength λ and the vertical axis 111 is the intensity I) is obtained. When a three-band comb filter is used, the broadband light source eventually becomes light with three corresponding wavelength peaks at different wavelengths.

  Although the present invention has been described based on specific embodiments, it goes without saying that the scope of the present invention includes a range that can be modified or changed by those skilled in the art within the scope of the claims.

It is a schematic diagram of an example of a defect detection system on a wafer or a processed semiconductor substrate. It is the schematic which shows an example of arrangement | positioning of the illuminating device of the apparatus which concerns on this invention, and a detection apparatus. In one embodiment of arrangement | positioning of the illuminating device of this invention, and a detection apparatus, it is the schematic at the time of arrange | positioning a polarizing device in an illumination optical line. It is other embodiment of arrangement | positioning of the illuminating device of this invention, and a detection apparatus. In further embodiment of this invention, it is the schematic of an example in the case of providing the 1st and 2nd illuminating device and the 1st and 2nd detection apparatus. An example of possible arrangement of the illumination range of the wafer surface is shown. In further embodiment of this invention, it is schematic of an example in case an illuminating device and a detection apparatus are respectively arrange | positioned at a certain angle. It is the schematic which shows an example of how the whole wafer or the processed semiconductor element is test | inspected (scanning) using the apparatus which concerns on this invention. FIG. 5B is a detailed view when the detection device is a trilinear detector in the arrangement shown in FIG. It is other embodiment of a detection apparatus in case a detection apparatus consists of a some detection chip. It is one embodiment of a detection apparatus in case a detection apparatus consists of a two-dimensional detection chip. In one embodiment of arrangement | positioning of an illuminating device and a detection apparatus, it is the schematic at the time of arrange | positioning DMD in an illumination optical line. FIG. 2 is a schematic diagram illustrating an example of possible illumination patterns on a wafer surface generated using DMD. An example of the spectrum of the light radiated | emitted from a linear light source is shown. It is a graph which shows an example of the intensity | strength characteristic of the light source which can be adjusted continuously. It is a graph which shows an example of the intensity | strength characteristic of the light radiated | emitted from LED. It is the schematic of an example of a corresponding spectrum illumination band (plurality) obtained when using the light source of a broadband band.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 System 3 Cartridge element 5 Measuring unit 9 Transfer mechanism 11 Housing 12 Mounting range 13 Display 14 Keyboard 15 Computer 20 Illumination device 20a Illumination light line 21 Detection device 21a Detection light line 21b Data line 22 Wafer surface 23 Wafer 25 Light splitter ( Beam splitter)
26 Range 27 Polarizing device 28 Support means 30 Normal 31 Lens 32 Optical device 35a, 35b Illumination area 41 (first) angle 42 (second) angle 55 (two-dimensional) detection chip 60 illumination spot 64 die 65 illumination device 66 Digital Modulator (DMD)
67 Light source 70 Spectral (or dispersion) element 85 Illumination pattern

Claims (32)

One or more illuminating devices respectively disposed in one illuminating light line, the one or more illuminating devices illuminate an illumination spot on the wafer surface, and an illuminating device which is a continuous light source;
A detection device disposed within one detection optical line having a predetermined spectral sensitivity and recording data from the one or more illumination spots on the wafer surface;
An imaging device that generates relative movement between the wafer surface and the detection device, whereby the illumination spot moves in a scanning direction in a zigzag manner and passes (scans) the entire wafer surface. An imaging device,
The one or more illumination spots are detected in a plurality of different spectral ranges;
A wafer inspection apparatus.   The inspection apparatus according to claim 1, wherein a polarizing device is arranged downstream of one or more illumination devices in each illumination light line.   An illumination region having a illumination pattern disposed on a downstream side of the one or more illumination devices and having an illumination pattern on the surface of the wafer that produces a plurality of positionally different ranges with respect to wavelength and / or intensity. The inspection apparatus according to claim 1, wherein the inspection apparatus is formed above.   The inspection apparatus according to claim 1, wherein the illumination device includes a light source that emits light having a plurality of intensity peaks discretely formed at different wavelengths.   The inspection apparatus according to claim 1, wherein the illumination device is a light source that can be continuously adjusted so that each of the illumination devices can be adjusted to a necessary wavelength range.   The inspection device according to claim 1, wherein the illumination device includes one or more LEDs.   The inspection apparatus according to claim 1, wherein the illumination device is a broadband light source that can be adjusted to each wavelength or wavelength range by a corresponding filter.   The inspection apparatus according to claim 1, wherein the detection apparatus is a line camera.   The inspection apparatus according to claim 1, wherein the detection apparatus includes a trilinear detector including an appropriate wavelength filter in each line of the trilinear detector.   8. The detection device according to any one of claims 1 to 7, characterized in that it comprises three photosensitive detection chips arranged in association with a spectroscopic or dispersion device so that each detection chip receives a different wavelength. The inspection device described.   The detection device includes a two-dimensional photosensitive detection chip having a spectral or dispersive element disposed upstream to direct light in different wavelength ranges onto different detection lines of the photosensitive two-dimensional detection chip. The inspection apparatus according to claim 1, wherein:   12. A beam splitter according to any one of the preceding claims, characterized in that a light splitter (beam splitter) is provided for making the light of the illuminating device kolinear with the detection light line of the detection device. The inspection device described in 1.   The inspection apparatus according to claim 12, wherein the beam splitter has polarization characteristics.   The illumination device and the detection device are arranged such that the illumination light line and the detection light line are inclined at an angle with respect to a normal line of the wafer surface, respectively. The inspection apparatus according to any one of 13.   The inspection apparatus according to claim 14, wherein the angles of the illumination device and the detection device are adjustable.   The inspection apparatus according to claim 1, wherein the one or more illumination devices generate illumination regions (a plurality) spatially separated in a scanning direction of the wafer surface. A first illuminating device configured as a continuous light source for irradiating an illuminating beam toward the wafer surface in the first illuminating light line;
A second illuminating device configured as a continuous light source for irradiating an illuminating beam toward the wafer surface in the second illuminating light line;
A first detection device defining a first detection optical line;
A second detection device defining a second detection optical line,
The wafer inspection apparatus, wherein the first and second detection devices have predetermined spectral sensitivity and detect data of one or more illumination ranges movable in the scanning direction on the wafer surface in a plurality of different spectral ranges.   18. The inspection apparatus according to claim 17, further comprising a polarizing device in at least one of the illumination light lines of the first and second illumination devices.   A digital modulator for generating an illumination area on the wafer surface is provided downstream of at least one of the two illuminators to generate a range on the wafer surface that is different from each other in terms of wavelength and / or intensity. The inspection apparatus according to claim 17, wherein the inspection apparatus is arranged on a side.   The inspection apparatus according to claim 17, wherein light from the first illumination device and the second illumination device is incident on a common illumination range on the wafer surface.   18. The inspection according to claim 17, wherein the light from the first illumination device and the second illumination device forms a range (a plurality) spatially separated in the scanning direction of the wafer surface. apparatus.   The second illumination device and the second detection device are arranged such that the second illumination light line and the second detection light line are inclined at an angle with respect to the normal of the wafer surface, respectively. The inspection apparatus according to claim 17, wherein the inspection apparatus is provided.   The inspection apparatus according to claim 22, wherein the angle formed by the second detection optical line is variable.   24. The inspection apparatus according to claim 17, wherein the first or second detection unit detects with monochromatic light or polychromatic light.   The said 1st and / or said 2nd illuminating device contains the light source which emits the light which has several intensity | strength peaks discretely formed in a different wavelength, The one of Claim 17 to 24 characterized by the above-mentioned. The inspection device described in 1.   25. The light source according to any one of claims 17 to 24, characterized in that the first and / or the second illumination device is a light source that can be adjusted continuously so that it can be adjusted to the required wavelength range, respectively. Inspection equipment.   The inspection apparatus according to any one of claims 17 to 24, wherein the first and / or the second illumination device includes one or more LEDs.   25. Inspection according to any one of claims 17 to 24, characterized in that the first and / or second illumination device comprises a broadband light source that can be adjusted to the respective wavelength or wavelength range by means of a corresponding filter. apparatus.   25. The inspection apparatus according to claim 17, wherein the first and / or the second detection apparatus is a line camera.   25. A device according to any one of claims 17 to 24, characterized in that the first and / or the second detection device comprise trilinear detectors with suitable wavelength filters in respective lines of the trilinear detectors. Inspection device.   The first and / or second detection device includes three photosensitive detection chips arranged in association with a spectroscopic or dispersion device so that each detection chip receives a different wavelength, The inspection apparatus according to any one of claims 17 to 24.   The first and / or the second detection device has spectral or dispersive elements arranged on the upstream side for directing light of different wavelength ranges (plurality) onto different detection lines of the photosensitive two-dimensional detection chip, 25. The inspection apparatus according to claim 17, further comprising a two-dimensional photosensitive detection chip.

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